We plan to organize and conduct the world's first international symposium on IgG4- related systemic disease (IgG4-RSD). We have secured commitments from the world's major researchers to participate in this Symposium. The expertise of our Organizing Committees spans the full spectrum of current knowledge about IgG4-RSD, and includes expertise from at least a dozen subspecialties within medicine, surgery, pathology, and radiology, among which are Rheumatology, Immunology, Allergy, Gastroenterology, Gastrointestinal Pathology, Vascular Pathology, Head &Neck Pathology, cross-sectional imaging (Radiology), and Hepatobiliary Surgery. We have developed an agenda that addresses the major questions confronting researchers and clinicians in the field today, from the many unknowns surrounding disease pathogenesis to the clinical spectrum of disease. The agenda will also cover diagnostic criteria, the development of disease activity indices, consensus discussions on standard approaches to therapy, and novel treatments. We anticipate several new directions emerging from the Symposium, including validation studies for outcome measures, more directed discussions about pathologic criteria for the disease across organ systems, plans for data and sample sharing, and the development of clinical trials. The proposed Symposium will have a galvanizing effect on the world's IgG4-RSD investigators at a time when the possibility of novel treatment approaches and new insights into pathophysiology exist.